Collinear, colinear, co-linear?

[oklameatman]

Would someone please define this term, with all of its multiple spellings? Which is the correct spelling?

 

[zz0468]

It's "collinear", and it's a mathematical term describing multiple points on a single line. In terms of antennas, it describes a multi-element antenna where the elements are placed end to end, rather than side to side as in a yagi.