Frontal means at the front, or facing straight at you. A frontal view of a building shows its face square on, no angle, nothing hidden round the side.
Most of the word's work is technical. Anatomy has the frontal lobe of the brain and the frontal bone behind the forehead; weather maps have a frontal system, the edge where one mass of air shoves into another. The military sense is a frontal assault or frontal attack, straight at the enemy rather than around the flank, and it has spread into argument: a frontal attack on government policy. Full-frontal means completely facing the viewer, and in film it describes nudity seen from the front. For everyday things use front, not frontal — it is the front door, the front row, the front page.
1adjectivefrontalAt, on, or facing the front.
“The photograph is a plain frontal view of the house.”
2adjectiveanatomyIn anatomy, of the front part of the head or brain.
“The scan showed damage to the frontal lobe.”
technical in this meaning — an editor’s judgement
3adjectiveweatherIn weather, of the boundary between two masses of air.
“A frontal system is moving in from the Atlantic.”
technical in this meaning — an editor’s judgement
4adjectivedirectDirect and open, aimed straight at its target.
“The speech was a frontal attack on the party leadership.”
Frontal was borrowed from New Latin frontālis, made from frons with the ending -ālis. In English it reads as front plus -al, the same ending that turns nation into national and centre into central, and French carries the word in exactly the same shape: frontal.
New Latin
frontālis
English, today
frontal
Borrowed from New Latin frontālis, from frons + -ālis, equivalent to front + -al; cognate of French frontal. a doublet of frontalis.
Etymology from Wiktionary, CC BY-SA