As straight or exact as a rule. Also as adv.: exactly, precisely. Obsolete. rare.

Directly, in a straight line. Obsolete. (Cf. diametral, adj. 1b.)

So as to be square; in a rectangular form or position; directly in line or in front.

In a position directly square with, or opposite to, some line or object; in a straight or direct manner.

In a collinear way; in the same line.