This subject came up when I was reading alt.usage.english
many years ago.
The original thread was spawned by the juvenile riddle
to which the correct answer is:
Because there's a mile
between the first and last letters.
A prompt response from one poster was that Beleaguered
must therefore be a longer word
since a league
is three mile
That was when the thread took off:
"That doesn't count because it requires you to add too many letters
is longer, because the AU
it contains is an astronomical unit
"In that case glyph
contains a light year
"She spelt Beleagered
and so on and so forth.