投师

投师	tóu shī	to join a guru for instruction
投	tóu	to throw (sth in a specific direction: ball, javelin, grenade etc) / to cast (a ballot) / to cast (a glance, a shadow etc) / to put in (money for investment, a coin to operate a slot machine) / to send (a letter, a manuscript etc) / to throw oneself into (a river, a well etc to commit suicide) / to go to; to seek refuge; to place oneself into the hands of / (coll.) to rinse (clothes) in water
师	Shī	surname Shi
师	shī	teacher / master / expert / model / army division / (old) troops / to dispatch troops