pile

drop, leave
Please do not leave litter after your picnic.

clean up, clear up, pick up

be strewn
Litter was strewn all over the field.

basket, bin (BrE)
lout (BrE) (litterbug in AmE)
The local council has pledged to clamp down on litter louts.

Litter is used with these nouns as the subject:
wrapper

Litter is used with these nouns as the object:
desk, floor, ground, landscape, sidewalk, street