no matter what it is; in every case; whatever the matter
Fixed expression meaning 'in any matter' or 'whatever the case may be'. Often used to introduce a general statement or habitual reaction.
No matter what it is, preparation is important.
He complains about everything, no matter what it is.
Standard kanji spelling for this expression.
Alternate kanji spelling using 付ける; less common but attested.
Combination of 何事 (what thing, everything) + につけ (whenever, in the case of). The につけ part is a classical conditional form of 付く, now used in fixed expressions.