http://www.etymonline.com/index.php?term=dildo
dildo (n.) Look up dildo at Dictionary.com 1590s, perhaps a corruption of Italian deletto "delight," from Latin dilectio, noun of action from diligere "to esteem highly, to love" (see diligence). Or (less likely) of English diddle. "Curse Eunuke dilldo, senceless counterfet" ["Choise of Valentines or the Merie Ballad of Nash his Dildo," T. Nashe, c. 1593] A classical Latin word for one was fascinum (see fascinate). In later English sometimes a French word, godemiche, was used (1879).
https://en.wikipedia.org/wiki/Dildo#Etymology
The etymology of the word dildo is unclear. The Oxford English Dictionary (OED) describes the word as being of "origin unknown".[1] One theory is that it originally referred to the phallus-shaped peg used to lock an oar in position on a dory (small boat). It would be inserted into a hole on the side of the boat, and is very similar in shape to the modern toy. It is possible that the sex toy takes its name from this sailing tool, which also lends its name to the town of Dildo and the nearby Dildo Island in Newfoundland, Canada. Others suggest the word is a corruption of Italian diletto "delight".[2] It has also been noted that the word dildo has similarity to "dill", a pickled cucumber, which is a vegetable that has been used as a natural dildo.
According to the OED, the word's first appearance in English was in Thomas Nashe's The Choice of Valentines or the Merie Ballad of Nash his Dildo (c. 1593).[Note 1] The word also appears in Ben Jonson's 1610 play, The Alchemist. William Shakespeare used the term once in The Winter's Tale, believed to be from 1610 or 1611, but not printed until the First Folio of 1623.[Note 2]
The phrase "Dil Doul", referring to a man's penis, appears in the 17th century folk ballad "The Maids Complaint for want of a Dil Doul".[3] The song was among the many in the library of Samuel Pepys.
An olisbos (pl. olisboi) is a classical term for a dildo, from Greek ὄλισβος.[4] i.e. a dildo that was usually made of leather. A godemiché is a dildo in the shape of a penis with scrotum.
In some modern languages, the names for dildo can be more descriptive, creative or subtle—note, for instance, the Russian фаллоимитатор (literally "phallic imitator"), Hindi दर्शिल्दो darśildō, Spanish consolador "consoler" and Welsh cala goeg "fake penis".