Where does “self-energy” come from?

self-energy (English) comes from English energy, from Middle French énergie, from Late Latin energia, from Ancient Greek ἐνέργεια, from Ancient Greek ἐνεργής, from Ancient Greek ἐνεργός, from Ancient Greek ἐν-, from Ancient Greek ἐν — Creates collective nouns, which refer to groups...

self-energy (English): the portion of the elementary particle's mass due...

Definitions

the portion of the elementary particle's mass due...

Ancestry of “self-energy”, step by step

Step	Language	Word	Meaning
1	English	energy	The impetus behind all motion and all activity;...
2	Middle French	énergie	—
3	Late Latin	energia	energy; efficiency
4	Ancient Greek	ἐνέργεια	activity, operation, vigour; workmanship;...
5	Ancient Greek	ἐνεργής	active, effective
6	Ancient Greek	ἐνεργός	at work, active
7	Ancient Greek	ἐν-	in, within; on
8	Ancient Greek	ἐν	in, on, at; among; in, at, or during the time of
9	Ancient Greek	δέρμα	skin, hide
10	Ancient Greek	γλυφή	carving, carved work; hole cut
11	Ancient Greek	-ῐ́ᾱ	{{l\|en\|-ia}}; "suffix forming abstract feminine...
12	Proto-Indo-European	-íh₂	—
13	Proto-Indo-European	-h₂	Creates collective nouns, which refer to groups...

Every word from Proto-Indo-European -h₂ →

self-energy — Etymology, Origin & Word History | Etymology Explorer