Load v. lode

from Garner's Usage Tip of the Day:

load, n.; lode.

Although they have similar etymologies, their meanings have fully diverged.

"Load" (in its basic senses) means "a quantity that can be carried at one time" or, by extension, "a burden" {a load of work} {a load off my mind}.

"Lode" carries the narrow meaning "a deposit of ore," as well as the figurative sense "a rich source or supply."The correct phrase, then, is "mother lode" (= an abundant supply), not "mother load."

Although dozens of headline writers have used "mother load" as a pun (usually in reference to pregnant women), some have fallen into true error -- e.g.:

• "She worked as a computer programmer, but kept plugging away at the music. And finally, she hit the mother load [read 'mother lode']." Tony Kiss, "Messina Never Gave Up Dream of Music Career," Asheville Citizen-Times, 3 Nov. 1996.
• "This site is a mother load [read 'mother lode'] of investing and financial planning information." Ted Sickinger, "Web Review," Kansas City Star, 6 Apr. 1997.