noun, na-adjective
high spirits; go-go mood; enthusiasm
Describes a lively, energetic, and eager atmosphere or attitude. Often used in phrases like 行け行けムード.
パーティーは行け行けムードで盛り上がった。
The party got lively with a go-go mood.
行け行け！あと少しでゴールだ！
Go, go! Just a little more to the goal!
na-adjective
flashy and assertive; fashionably dressed and confident
Dated colloquial term, often used for a woman who is stylishly dressed and self-assured. The katakana spelling イケイケ is especially associated with this sense.
彼女はイケイケなファッションで注目を集めていた。
She attracted attention with her flashy, confident fashion.
na-adjective
Rare usage referring to rooms that are connected or adjacent. This sense is not common in modern Japanese.
この旅館には行け行けの部屋がある。
This inn has adjoining rooms.
Reduplication of the imperative form 行け (ike, 'go') from the verb 行く (iku). The interjection and energetic noun senses derive directly from this urging meaning. The dated slang sense likely developed from the idea of being 'on the go' or assertive. The rare 'adjoining rooms' sense may be a separate homophonous expression, but its origin is uncertain.