Undersea, submarine; underspan, subtend; underslinking, subterfuge.
In like manner the two pale are bracteoles which subtend the flower proper.
"Subtend" is from the Latin sub (under), and tendere (to stretch).
He did not define "subtend," supposing such words to be already understood.
The cones, about the size of a small walnut, bear spirally arranged imbricated scales which ...