24wks pg. At last sono I noticed that from my the baby in uterus to my short, . 4cm cervix was a large v-shaped void of nothing. Is this "funneling"?

Hard to say. An experienced perinatologist would always want to see images or to at least know the sonographer or sonologist who did the ultrasound study. Therefore, we cannot provide an answer for you here. However, if you are already considered high risk due to short cervix and/or history of preterm labor or birth, you are probably in the care of OB or mfm (maternal-fetal medicine) and could contact them.
Funneling. A cervix of only .4 cm is very short at 24 weeks. That v-shaped black area pointing to the cervical os is funneling. There are signs of an increased risk of a premature birth. A cervical cerclage or vaginal Progesterone are two therapies used in this situation.
Possible. Your description matches what funneling often looks like, but without seeing the images it is impossible to say. Since your cervix is short (0.4 cm you said?), they are likely following you closely and would be happy to tell you.