regardless of; irrespective of; no matter ...
Fixed expression used after nouns or question words to mean 'without being affected by' or 'without distinction'. Often follows words like 年齢, 性別, 国籍, or question phrases like 何, いつ, だれ.
See also: 問う
This event is open to participants regardless of age.
Lateness is not permitted, irrespective of the reason.
He helps me no matter when, at any time.
Negative continuative form of the verb 問う (to ask, to question). Literally 'without asking', it developed into a fixed expression meaning 'regardless of'.