委任[inin] charge
委任状[ininjou] commission
一任[ichinin] entrusting
引責辞任[insekijinin] taking responsibility upon oneself (and resigning)
解任[kainin] dismissal

帰任[kinin] return to one's post
共同責任[kyoudousekinin] joint responsibility
兼任[kennin] concurrent post
後任[kounin] successor
口任せ[kuchimakase] random talk

御食い初め[okuizome] weaning ceremony
為初め[shisome] outset
為初める[shisomeru] to begin to do
仮初[karisome] temporary
業界初[gyoukaihatsu] the industry's first ...

月初め[tsukihajime] beginning of month
最初[saisho] beginning
初めに[hajimeni] to begin with (used as an introduction)
初めは[hajimeha] at first
手初めに[tehajimeni] at first