正交

orthogonality

first month of the lunar year

straight / upright / proper / main / principal / to correct / to rectify / exactly / just (at that time) / right (in that place) / (math.) positive

to hand over / to deliver / to pay (money) / to turn over / to make friends / to intersect (lines) / variant of 跤[jiao1]

orthogonal group (math.)