Synonyms For "Hollow" :

1 syllable:

dig, hole

2 syllables:

core out, empty, holler, recessed, sunken

3 syllables:

cannular, cavernous, excavate, fistular, fistulate, fistulous, meaningless, tubelike, tubular, vacuous, vasiform

4 syllables:

nonmeaningful, reverberant