expression
most of all; extremely; supremely
Adverbial phrase meaning 'to the highest degree', used to emphasize adjectives or verbs. Often interchangeable with この上もなく.
この上なく幸せです。
I am supremely happy.
彼はこの上なく親切な人だ。
He is an extremely kind person.
Almost identical in meaning; この上もなく is slightly more emphatic with the addition of も.
Means 'more than anything', focusing on comparison, while この上なく is an absolute superlative.
From この上 (kono ue, 'beyond this') + なく (naku, adverbial form of ない 'not'), literally 'there being nothing beyond this'.