βυσσομέτρης
From LSJ
ἐν πίθῳ τὴν κεραμείαν μανθάνειν → in breaking many pots, the potter learns his craft | of those who undertake the most difficult tasks without learning the elements of the art | don't run before you can walk
English (LSJ)
ου, ὁ,
A measuring the deeps, epith. of a fisherman, AP6.193 (Stat. Flacc.).