Synonyms of entering

1 Syllable
creep, crack, sneak, crawl, slip
2 Syllables
probe, ingress, wriggle, inward, access, insert, inbound, ingoing, pierce
3 Syllables
arrive, invade, intrude, inflowing, inpouring, incoming, penetrant
4 Syllables
introduce, penetrating, penetrate, insinuate, introgression, infiltrate, immigrate, subjugation