expression, noun which may take the genitive case particle 'no'
trivial; insignificant; that little amount
Expresses that something is too small or insignificant to matter; often used dismissively or to downplay a concern. Functions as a noun-like expression with の or in phrases like それしきのこと.
それしきのことで怒るなよ。
Don't get angry over such a trivial thing.
それしきの金額なら気にしなくていい。
If it's that small an amount, you don't need to worry about it.
これしき means 'this little amount' (close to the speaker), while それしき means 'that little amount' (close to the listener or referring to something just mentioned).
あれしき means 'that little amount' (distant from both speaker and listener), while それしき is more immediate or refers to something just brought up.
Compound of それ (that) and しき (an old suffix meaning 'extent' or 'amount', related to だけ). The exact historical derivation of しき is uncertain, but it functions similarly to だけ or ほど in modern Japanese.