-ulus

From Latin -ulus (diminutive suffix).

-ulus

1. (taxonomy) used to form genus names, especially from other genus names, indicating smaller size

• -olus (after a vowel)
• -lus

From Proto-Italic *-elos (whence Faliscan -𐌄𐌋𐌏𐌔 (-elos)), from Proto-Indo-European *-elós, thematized from Proto-Indo-European *-lós.[1]

Cognate with Proto-Germanic *-ilaz and *-ulaz, whence no longer productive English -le (as in dimple and nozzle), Dutch -el, German -el.

• (Classical) IPA^(key): /u.lus/, [ʊɫ̪ʊs̠]
• (modern Italianate Ecclesiastical) IPA^(key): /u.lus/, [ulus] (stressed on the antepenult)

-ulus (feminine -ula, neuter -ulum); first/second-declension suffix

1. Used to form a diminutive of a noun, indicating small size or youth.
2. Used to form a diminutive of an adjective with diminished effect, indicating “somewhat” or “-ish”.
3. Used to form an agent noun or adjective from a verb.

The suffix -ulus is added to a noun to form a diminutive of that noun. Latin diminutives typically match the gender of the base word.

Examples:

‎rēx m (“king”) + ‎-ulus → ‎rēgulus m (“prince, petty king”)

‎virga f (“twig, rod, switch, staff”) + ‎-ulus → ‎virgula f (“little twig, small rod, wand”)

‎oppidum n (“town, settlement”) + ‎-ulus → ‎oppidulum n (“small town or settlement, village”)

‎calx f (“limestone, game counter”) + ‎-ulus → ‎calculus m (“pebble, little stone”)

The allomorph -olus, -ola, -olum is regularly used to form diminutives of nouns ending in -ius, -ia, -ium, -eus, -ea, -eum.

When added to an adjective, it forms a diminutive of that adjective:

‎albus (“white”) + ‎-ulus → ‎albulus (“whitish”, literally “a little white”)

When added to a verb, it forms an adjective with the relational meaning “doing …” or “tending to …”:

‎tremō (“tremble”) + ‎-ulus → ‎tremulus (“trembling, tending to tremble”)

‎crēdō (“believe”) + ‎-ulus → ‎crēdulus (“believing, tending to believe”)

First/second-declension adjective.

• → English: -ule
• Galician: -ó, -oa (no longer productive)
• Greek: -ούλα (-oúla)
• Italian: -olo, -ola
• Sicilian: -ulu, -ula
• Spanish: -uelo, -uela