frons

Frons, frontis, f., third declension: the forehead, and by extension the front of anything - a building, a battle line, the outer edge of a book roll. A fronte and a tergo are the standard pair for front and rear.

Romans read the face as evidence, so frons carries character with it. Frons is where shame shows, which is why perfricare frontem, to rub your brow until it stops blushing, means to shed your shame altogether, and why English inherited effrontery. The trap is a second noun, frons, frondis, f., meaning foliage: the nominatives are identical and only the genitive separates them, so a wood full of foreheads is a real risk on a first reading.