Past tense of 'gull': deceived or tricked someone into believing something false.
From the verb 'gull,' which itself may derive from the gull bird (easy to catch), or possibly from earlier slang. The past tense follows regular English '-ed' formation.
People have been using bird names to insult intelligence for millennia—'dodo,' 'birdbrain,' 'gull'—which reveals how older cultures saw birds as less clever than humans, even though we now know many are quite intelligent!
Complete word intelligence in one call. Free tier — 50 lookups/day.