TIMOPSC
Make words with C
Never: plural or third-person -S suffix
CIST COCCI COCO COMIC COMMIT COMPOST COOP COSMIC COSMOS COST ISOTOPIC MIMIC MIOTIC OPTIC OPTICIST COSMISM COSMIST OPTIMISTIC OSMOTIC SCOOP SCOOT SITCOM STOIC STOICISM TOPIC
Pangrams: OPTIMISTIC