Do you know ghouls from goblins and ghosts?
c.1400, chokkeful "crammed full," possibly from choke "cheek" (see cheek (n.)). Or it may be from Old French choquier "collide, crash, hit" (13c., Modern French choquer), which is probably from Germanic (cf. Middle Dutch schokken; see shock (n.1)).
Absolutely full; crammed; chockablock
[perhaps 1400+, certainly 1751+; origin uncertain; perhaps ''full to the point of choking'']