3 letters

@wolfe63 said
sawgrass

TMI

@orangutan said
PosTMIstress.

ABJ

(but not a word starting with these).

@wolfgang59 said
abject

LKM

@orangutan said
ABJ - but in the middle of a word.

@handyandy said
frabjous

JEJ

@orangutan said
JEJune
(I had to check that this was an English word - I thought it was French, turns out it's from Latin).

RSN

@kewpie said
paRSNip

Y W H

@orangutan

Manxman

DYG

@wolfgang59 said
@orangutan

Manxman

DYG

@orangutan said
NGU

@handyandy said
hangup

XAD

@handyandy said
hangup

XAD

@kewpie said
hexadecimal

P T R

@wolfgang59 said
sceptre

MOJ

@orangutan said
NEH