Synonyms of decent-sized

1 Syllable
great, gross, good, big
2 Syllables
hefty, strapping, decent, spacious, major, tidy, burly, husky, whopping, goodly, jumbo, largish, goodliest, ample
3 Syllables
sensible, sizable, capacious, ponderous, substantial, massive
4 Syllables
respectable, voluminous, extensive
5 Syllables
comprehensive