Ephippiger ephippiger, a primarily insectivorous bushcricket common to southwestern Europe.

long ago / far into the past

Alternative form of back to the drawing board

(linear algebra) A method of solving linear systems that have been transformed into row echelon form. / (combinatorics) A method of solving recurrence relations.

Alternative form of with one hand tied behind one's back

(informal, figuratively) Easily, without much effort. / (informal, figuratively) Hampered by factors outside one’s control.

Alternative spelling of backbone

plural of back-bone

(education) A rigorous educational program for high school students, focused on developing critical thinking, collaboration, and reflection skills.

present participle of back out