12-Letter Words Start with 'is'

There are 13 12-letter words that start with 'is'.

isoantigenic	isobutylenes	isochronally
isochronisms	isodiametric	isoenzymatic
isolationism	isolationist	isomorphisms
isoprenaline	isothermally	isotonically
isotopically

Note: These 13 12-letter words that start with 'is' are found from the USA & Canada version of the tournament Scrabble word list.

Also see words start with iso, isa, isl, iss, isc, ist, ise, isb, isi, ism.

3-letter words start with 'is' (1)
4-letter words start with 'is' (3)
5-letter words start with 'is' (7)
6-letter words start with 'is' (17)
7-letter words start with 'is' (42)
8-letter words start with 'is' (69)
9-letter words start with 'is' (75)
10-letter words start with 'is' (44)
11-letter words start with 'is' (15)
12-letter words start with 'is' (13)
13-letter words start with 'is' (16)
14-letter words start with 'is' (8)