thumb|250px|The long dedication to Lugus from [[Peñalba de Villastar]]
Lugus (sometimes Lugos or Lug
and Erich Hamp have proposed that the name derives from a proto-Celtic word meaning "oath" (either or ). John T. Koch has taken this hypothesis up, and proposed that the early Irish oath tongu do dia toinges mo thúath is a suppressed oath to Lugus. Minority etymologies derive "Lugus" from the name of the Norse god Loki, and supposed Gaulish ("raven").
|-
|(or
|
|Inscribed on a stele. Found in , Burgos, Spain.
|Gaulish
|RIG I G-159
|The inscription is probably an ownership mark, so at most records a theophoric personal name. but in dedications to Lugus the plural form ("Lugoves" or "Lucoves" that is, "the fortress of Lugus". Attempts have been made to analyse the name as ("luminous" or "clear") + ("hill"), bolstered by a medieval etymology which gives the gloss ("shining mountain").
The place-name Lugdunum is attested, in its cognate forms, as the name of as many as twenty-seven locations. and two cities of unclear location in North East England and Germania Magna.
The god they reverence most is Mercury. They have many images of him, and they regard him as the inventor of all arts, the god who directs men on their journeys, and the most powerful helper in trading and getting money. Next to him they reverence Apollo, Mars, Jupiter, and Minerva, about whom they have much the same ideas as other nations.
Caesar here employs the device of interpretatio romana, in which foreign gods are equated with those of the Roman pantheon.