Chirres vs Chirred - What's the difference?

As verbs the difference between chirres and chirred

is that chirres is (chirre) while chirred is (chirr).

(head)

(chirre)

(chirr)

(obsolete) To coo like a pigeon.

(Webster 1913)

(head)

(chirr)

(chirre)

(en verb)

To make a prolonged trilling sound of an insect (e.g. a grasshopper, a cicada).

(en noun)

The trilled sound made by an insect.