like nailing jelly to the wall

if something is like nailing jelly to the wall, it is impossible to understand or describe it exactly Writing a history of the period is like nailing jelly to the wall.

Common Names:

Name	Pronounced	Usage
Tijmen	-	Dutch
Prokopiy	prah-KO-pee	Russian
Pyrrhus	PIR-əs (English)	Greek Mythology (Latinized), Ancient Greek (Latinized)
Heribert	HE-ree-bert	German
Atrides	['ætridəs]
Ealair	-	Scottish