Oblique means slanting, or expressed indirectly. An oblique angle, an oblique reference, oblique criticism.
The indirect sense is the useful one: an oblique reference points at something without naming it, which is how a great deal of criticism is delivered in polite settings. In geometry an oblique angle is any that is not a right angle.
1adjectiveobliqueSlanting, or expressed indirectly.
“The evening sun threw long, oblique shadows across the field.”
oblique is a quality.
Latin obliquus means slanting or sideways, of uncertain further origin.
Latin
oblīquus (also spelled oblīcus) — slanting, sideways, indirect, envious
Middle French
oblique
English, today
oblique
From Middle French oblique, from Latin oblīquus (also spelled oblīcus) (“slanting, sideways, indirect, envious”).
Etymology from Wiktionary, CC BY-SA