17 entries under opening topic. ×

7
peephole
6
keyhole
5
pinhole
4
loophole
4
hole(noun, break, channel, passage)
4
pigeonhole
2
eyelet
2
mousehole
2
outlet(noun, place, release, escape)
2
vent(noun, break, channel, passage)
1
aperture(noun, break, bow, channel)
1
fontanel
1
foramen
1
perforation
0
puncture
0
slot
0
transforation
11 years ago|3.3k views|share |citing 
APASmart Define. (2015). porthole thesaurus. Retrieved September 27, 2026, from https://smartdefine.org/porthole/thesaurus/synonyms
ChicagoSmart Define. 2015. "porthole thesaurus" https://smartdefine.org/porthole/thesaurus/synonyms (accessed September 27, 2026).
HarvardSmart Define 2015, porthole thesaurus, Smart Define, viewed 27 September, 2026, <https://smartdefine.org/porthole/thesaurus/synonyms>.
MLASmart Define. "porthole thesaurus" 10 April 2015. Web. 27 September 2026. <https://smartdefine.org/porthole/thesaurus/synonyms>