godan verb (-su), transitive verb
use for a long time; have long in use
Rare verb meaning to keep and use something over a long period, implying wear or familiarity. Modern Japanese typically uses 長く使う or 使い古す instead.
祖父が持ち古した道具は、今も現役だ。
The tools my grandfather used for a long time are still in service today.
使い古す means to use something until it becomes old or worn out, focusing on the result. 持ち古す is rarer and emphasizes the duration of possession and use.
Compound of 持ち (continuative form of 持つ 'to hold, have') and 古す (verb-forming suffix meaning 'to make old through an action'). The exact historical derivation is uncertain.