走失

走失	zǒu shī	lost / missing / to lose (sb in one's charge) / to get lost / to wander away / to lose (flavor, freshness, shape, hair, one's good looks etc) / to lose meaning (in translation)
走	zǒu	to walk / to go / to run / to move (of vehicle) / to visit / to leave / to go away / to die (euph.) / from / through / away (in compound verbs, such as 撤走) / to change (shape, form, meaning)
失	shī	to lose / to miss / to fail