perpendicular adj.
1 pointing straight up
VERBS be
ADV. almost, nearly an almost perpendicular staircase
2 at an angle of 90° to sth
VERBS be
ADV. exactly | almost | mutually two mutually perpendicular directions
PREP. to The axis of the moon will now be exactly perpendicular to that of the earth.
You can also check other dicts: perpendicular (English, 中文解释 ), wordnet sense, Collins Definition