"Junior" and "Senior" in other languages read as the family name: Antonio Pavlović mlađi gives family mlađi #661

SUFFIX_WORDS holds English and a few Romance generational words. In other languages the word becomes the family name and the real surname drops to middle:

Мария Георгиева младши            → middle 'Георгиева', family 'младши'
Antonio Pavlović mlađi            → middle 'Pavlović', family 'mlađi'
Kemal Sunal kıdemli               → family 'kıdemli'
Gediminas Baravykas jaunesnysis   → family 'jaunesnysis'
Daniel O'Reilly sóisearach        → family 'sóisearach'
आदित्य मित्तल जूनियर                → family 'जूनियर'
Nagy János ifj.                   → family 'ifj.'

Candidates (from the ilib-name test suite, Apache-2.0, plus Hungarian ifj./id.): младши/старши (bg), mlađi/stariji (hr/sr/bs), kıdemli (tr), nuorempi/vanhempi (fi), jaunesnysis/vyresnysis (lt), sóisearach/sinsearach (ga), जूनियर/सीनियर (hi), ifj./id. (hu).

Collision check (tools/name_usage.py; a suffix claim acts on the last word, so surnames are the risk): none of the bg/hr/tr/lt/ga/hu forms is a US Census surname or has Wikidata bearers. nuorempi has one of each, which is noise.

Caveat: ilib's suffix data is partly machine-translated; several of its trailing words mean "retired". Each word needs checking against real usage before it's added, and some languages may use a different form (an abbreviation, or a form that agrees with the name's gender).

Out of scope: Hungarian ifj. placed before the name (ifj. Kovács János is currently a title via the period-abbreviation shape rule).