15-Letter Words Start with 'op'

There are 13 15-letter words that start with 'op'.

openheartedness	openmouthedness
operationalisms	operationalists
operativenesses	ophthalmologies
ophthalmologist	ophthalmoscopes
ophthalmoscopic	opinionatedness
opportunenesses	opprobriousness
optoelectronics

Note: These 13 15-letter words that start with 'op' are found from the USA & Canada version of the tournament Scrabble word list.

Also see words start with ope, opp, opt, opa, opi, oph, opu, ops, opo.

3-letter words start with 'op' (3)
4-letter words start with 'op' (7)
5-letter words start with 'op' (10)
6-letter words start with 'op' (21)
7-letter words start with 'op' (37)
8-letter words start with 'op' (55)
9-letter words start with 'op' (63)
10-letter words start with 'op' (41)
11-letter words start with 'op' (28)
12-letter words start with 'op' (19)
13-letter words start with 'op' (20)
14-letter words start with 'op' (14)
15-letter words start with 'op' (13)