The ABI armhf stand for ARM Hard-Float but what is el an abbreviation for in armel?
el stands for little-endian; see the email explaining (briefly) the decision; the follow-up emails contain more information. Endianness isn't the most distinguishing feature of
armel, but that's the name that was chosen...
Further evidence is in Wookey's Debconf7 talk introducing the
armel architecture; in the video at 26:47 he explicitly says "
armel, basically little-endian ARM".
Other architectures using
el in the same way include
As pointed out by Kurt,
el is the initials of "little-endian" read in little-endian order.