In response to the query about whether to use a space or not in
breastfeeding, and in my capacity as a technical editor, I did a little
research.  It's very interesting to observe social history through language.

The Merriam Webster's Collegiate Dictionary, 10th ed. (1994) has citations
for "bottle-feed" and "breast-feed."  The term bottle-feed is cited as
having come into use in about 1865, and the definition is "to feed (as an
infant) with a bottle."  The term breast-feed is cited as having come into
use in 1903, and is defined, "to feed (a baby) from a mother's breast rather
than from a bottle."  I would say that this is a case of the creation of a
retronym.  Here's an example of a retronym: first we had "baseball", which
was always played in daylight.  Then we got lighted fields, and "nighttime
baseball" was born.  Finally, "nighttime baseball" became the norm and the
term "daytime baseball" was coined to refer to what originally had just been
baseball.  Based solely on these two dictionary references, the history of
the term would be that the normal way to feed babies was with breasts, so
until bottles were introduced, they were just fed.  In 1865, the term
bottle-feed was introduced to describe the new phenomenon.  in 1903,
breast-feed was introduced to differentiate what used to be normal from
bottle-feeding.  Finally, the definitions sadly reflect today's social
practice: Bottle-feeding is just to feed with a bottle, but breast-feeding
is the exception used "rather than from a bottle."

For U.S. usage, anyway, it appears that the current acceptable form is with
the hyphen.  Hyphens, however, are only needed when the word is not easily
understood without them.  Obviously, the word "breastfeed" is just as easy
to understand with or without the hyphen.  I always try to eliminate
unnecessary punctuation, so I say, leave out the hyphen.

Margaret K.K. Radcliffe               [log in to unmask]
Dept. of Mining & Minerals Engr.
Virginia Tech, Blacksburg, VA