A 7 letter word starting with c is confirm.
vocalic or voltaic.
convene also collect
Cash is a 4 letter word that starts with c and ends with h.
A science word that is six letters ans starts with the letter c is convex.
coxcomb
Chronic
chaotic
Company
czarism
CHARITY
camphorcentaurchamberchaptercharmerchartercheaperchopperchowdercleanercleaverclimberclippercountercreamercreatorcrisper
Silicic
Cantata
vocalic or voltaic.
Cryptic
success
compass