shift vs diphthongize

shift is a noun but diphthongize is not a noun.

Word	Noun	Adjective	Verb	Adverb
shift	Yes	No	Yes	No
diphthongize	No	No	Yes	No

As verbs, diphthongize is a hyponym of shift; that is, diphthongize is a word with a more specific, narrower meaning than shift:

Other hyponyms of shift include transition, shift, break, channel-surf, surf, jump, leap, diphthongise, cut, break.

shift (noun)	diphthongize (noun)
the act of moving from one place to another
the act of changing one thing or position for another
a loose-fitting dress hanging straight from the shoulders without a waist
a woman's sleeveless undergarment
the key on the typewriter keyboard that shifts from lower-case letters to upper-case letters
an event in which something is displaced without rotation
a qualitative change
a crew of workers who work for a specific period of time
(geology) a crack in the earth's crust resulting from the displacement of one side with respect to the other
the time period during which you are at work

shift (verb)	diphthongize (verb)
make a shift in or exchange of	change from a simple vowel to a diphthong
move and exchange for another
lay aside, abandon, or leave for another
move from one setting or context to another
change in quality
change gears
change phonetically as part of a systematic historical change
use a shift key on a keyboard
change place or direction
move very slightly
move around
move abruptly
move sideways or in an unsteady way