From Longman Dictionary of Contemporary Englishsidekickside‧kick /ˈsaɪdˌkɪk/ noun [countable] informal WITHsomeone who spends time with or helps another person, especially when that other person is more important than they are
Examples from the Corpus
sidekick• In the continuing attempt to out-Mario Mario, Sega has now given Sonic a sidekick, Tails the fox.• The player races around the world, chasing the elusive villain Carmen Sandiego and her many evil sidekicks.• Sherlock Holmes and his sidekick Dr Watson• Tom and his sidekick Larry sauntered into the bar, plainly looking for a fight.• The humour was devastatingly fresh and Vic and his sidekick Bob saw life from a sort of vaguely diagonal point of view.• His sidekick Sergeant Lewis is a Labour voter.• He usually plays older brothers, blushing patsies, jumpy sidekicks, all-smiles Ivy Leaguers.• Hardened matrons and their brick outhouse sidekicks clasped their hands in front of their chins and let their eyes become wet. 