Let us start with the word for zero. Latin did not have a word for zero as a numeral the way we do today. Therefore, they did not have a name for that number either. The Romans did have a word nihil, which meant ‘nothing’. It came from the word-parts (morphemes) ne‑ ‘not’ and hilum ‘a small thing, a trifle’ and thus it meant literally something like ‘not a thing’ or ‘nothing’. English borrowed this word as nil in the 19th century. Eng. nil is used as a noun, meaning ‘nothing, no amount, zero’ (OED) or, less frequently, as an adjective, meaning ‘containing, reporting, or consisting of nothing; non-existent’ (OED), as in nil results. As a noun, it is used in Britain (but not in the US) to report non-scoring in sports games.
The Latin word nihil has no descendants in Spanish, whether patrimonial or learned. The English noun nil typically translates as cero or nada, e.g. Its value is nil ‘Su valor es cero’, ‘No vale nada’. Adjectival Eng. nil typically translates into Spanish as nulo/a, as in resultados nulos ‘nil results’. Sp. nulo is a 16th century loanword from Lat. nūllus ‘none’, a compound formed from ne‑ ‘not’ plus ūllus ‘any’.
English and Spanish share the derived, New Latin cognate words Eng. nihilism /ˈnaɪ̯.(h)ɪ.lɪ.zəm/ ~ Sp. nihilismo /ni.i.ˈlis.mo/, which refer to a philosophical doctrine that claims that there is no inherent purpose to life (existential nihilism) or no inherent morality (moral nihilism). The name of this ‘doctrine of negation’ is the New Latin word Nihilismus, first coined in German in the early 19th century. Believers in these philosophical doctrines are known, respectively, as Eng. nihilists ~ Sp. nihilistas. The term has also been used in psychology to name certain mental disorders, for example, and in politics to refer to ‘total rejection of established laws and institutions’ (RHW).
The words for ‘zero’ in English and Spanish are the cognates Eng. zero (/ˈzɪɹ.oʊ̯/ or /ˈzi.ɹoʊ̯/) and Sp. cero (/ˈθe.ɾo//), which are obviously not related to Latin nihil. That is because these words are both derived from or are loanwords from Medieval Latin zephirum, which comes from Arabic صِفْر (ṣifr), meaning ‘nothing, cipher’, which seems to be a translation of Sanskrit śūnya-m ‘empty place, desert, naught’. The word was first used in Europe in Medieval Latin, by Italian mathematician Leonardo Fibonacci, in 1202.
English got this word around 1600 from Italian zero, from an earlier *zefiro, perhaps through the mediation of French zéro (attested around 1515). However, the word cipher (see below) is already attested with the meaning ‘zero’ by 1400 in English. Ultimately the source is the Arabic word transliterated as ṣifr or çifr. The first documentation of the word cero in Spanish is also from around 1600. Later on, Spanish respelled all the ze combinations to ce, of equal pronunciation. This explains the appearance of the letter c instead of z in this word (another example: cebra, from an earlier zebra).
The reason that these words come ultimately from Arabic is that it was the Arabs who brought the concept of a zero ‘number’ to Europe during the Middle Ages and replaced the cumbersome Roman numerals (I = 1, V = 5, etc., cf. §19.21) with so-called Arabic numerals (Sp. números arábigos), which depend crucially on the number zero. Arabic numerals are also known as Hindu numerals or Hindu-Arabic numerals (Sp. números indoarábigos), since the Arabs got the system from India, albeit indirectly through Persia. The Arabic word was a translation or calque of the Sanskrit word śūnya, which literally meant ‘empty’ (OED).
The Medieval Latin word zephirum that zero and cero came from originally meant ‘zero, nothing’, like these words do now. Eng. cipher and Sp. cifra were originally used with this meaning before adopting the Italian zero. Eventually, these other derived words started being used for extended meanings in different contexts and in different languages. So, for instance, they came to mean ‘numeral’, that is, any number, in Spanish and French. Thus, Modern Spanish cifra, ultimately derived from Med.Lat. zephirum, just like Sp. cero but without the Italian mediation, means ‘figure, number, digit, amount’, as in un número de tres cifras ‘a three digit number’ or La cifra es muy elevada ‘the figure (amount) is very high’ (cf. the French cognate chiffre /ˈʃifʀ/, with the same meaning).
Later in the 16th century, this same word came to mean ‘coded message’ in French and Italian, from where it passed to English as cipher or cypher /ˈsaɪ̯.fəɹ/. The reason for this change is that early codes typically substituted letters with numbers. The Spanish word cifra has been used in the past to mean ‘cipher’, through French and English influence, but the best equivalents for cipher in Spanish are código and clave, not cifra. So, as we can see, Eng. cipher and Sp. cifra are cognates, but they are not very good friends.
The English numeral zero has been converted into a verb in English, in particular as the phrasal verb zero in (on) (for more on phrasal verbs, see Part I, Chapter 4, §4.8.3). The verb to zero first appeared in 1909 with the meaning of turning the setting in a rifle scope to zero. The phrasal verb to zero in is from around 1944 and it means ‘set the sights of (a gun) for firing’ or ‘take aim at or focus attention on’ (COED). This phrasal verb can be translated into Spanish as apuntarle directamente a, when talking about a target, or centrarse en, concentrar la atención en or sobre, when talking about an issue or problem (OES).
 The Arabic number system is one of the most important developments in the history of mathematics, primarily because it included the zero in positional notation. Most historians believe that it originated in India by AD 700, although the positional system may have had a precedent in China.