by half
An intensifier used to indicate that some quality is excessive or more than is necessary. Used in the form "too (something) by half." Primarily heard in UK. That child is too noisy by half! Liam is too clever by half, winning every debate he gets into.
by half
Considerably, a great deal, as in He was too good a cook by half for this small restaurant. [c. a.d. 1000] Contrast by halves.
by half
1. By a considerable extent.
2. By an excessive amount: too clever by half.