Opheltes was a son of Lycurgus and Amphithea (or Eurydice). He was killed by a snake as a child and was posthumously renamed Archemoros (which name see for his story). We can consider two possible sources for his name.

He was either 'helpful', from ophello, 'to help' or else he was 'crushed by a snake' (which we know he was), from ophis, 'snake' and eilo, 'to press tight', 'force together'. Either would suit him, the first possibly propitiously. (In fact 'helpful' is more an epithet than a real name, as indeed is his subsequent name, Archemoros.)