Word: siftproof
Part of speech: Adjective
Syllables: sift
proof
Definition: Designed so that loose powder etc. cannot sift out during transit.
Morphemes:
Affix: sift
Language: en
PoS: Verb
Meaning: To sieve or strain (something).
Affix: -proof
Language: en
PoS: Suffix
Meaning: Used to form adjectives denoting an impervious or impenetrable quality.