咥える[kuwaeru] to hold in one's mouth
咥えこむ[kuwaekomu] to hold fast deep in (one's mouth or other orifice, often used in a sexual context)

指を咥える[yubiwokuwaeru] to look on enviously while doing nothing

のめり込む[nomerikomu] to be completely absorbed in
圧し込む[heshikomu] to push into
意気込む[ikigomu] to be enthusiastic about
引込む[hikikomu] to draw in
引摺り込む[hikizurikomu] to drag in

引っ込み[hikkomi] retreat
引込思案[hikkomijian] reserved
引っ込む[hikkomu] to draw back
引っ込める[hikkomeru] to draw in
運び込む[hakobikomu] to carry in

銜む[kukumu] to contain
銜える[kuwaeru] to hold in one's mouth
枚を銜む[baiwofukumu] (of a horse) to be gagged
轡銜[kutsuwa] bit (i.e. attached to a bridle)
銜えこむ[kuwaekomu] to hold fast deep in (one's mouth or other orifice, often used in a sexual context)

銜え箸[kuwaebashi] holding one's chopsticks in one's mouth (a breach of etiquette)
馬銜[hami] bit mouthpiece
横銜え[yokoguwae] holding horizontally in one's mouth
指を銜える[yubiwokuwaeru] to look on enviously while doing nothing