UCAL (ū'kăl, Heb. ’ūkhāl). A word of uncertain meaning found in Prov.30.1, regarded as a proper noun by many interpreters. If this is the correct interpretation, it is the name of one of two men to whom Agur addressed his proverbs. Others regard the word as a verb and translate it “I am faint.”

UCAL u’ kəl (אֻכָֽל, I am strong). One of two men—perhaps sons, disciples, or contemporaries—to whom Agur addressed his oracular sayings; the other was Ithiel (Prov 30:1). The name Ucal is not found anywhere else in the OT. The name Ithiel belongs to a Benjaminite (Neh 11:7). Neither the LXX nor the Vul. recognizes proper names here. For these and other considerations some scholars discard Ithiel and Ucal as proper names by rearranging the Heb. text (without changing the consonants), and the last three words of the v. are then rendered, “I have wearied myself, O God, I have wearied myself, O God, and am consumed.”

International Standard Bible Encyclopedia (1915)

(’ukhal (see below)): This name occurs along with that of Ithiel (Pr 30:1), both being taken by older interpreters as those of ancient sages. Some have suggested (see Toy, Proverbs, 519 f) that Ucal might be the "Caleol" of 1Ki 4:31 (Hebrew 5:11). Ucal was also explained as "I can," i.e. "I can maintain my obedience to God," just as Ithiel was taken to be "signs of God." Septuagint, Aquila, Theodotion do not take the words as proper names, and so BDB with others point this word as a vb., "(and) I am consumed" (wa’ekhel, for [~we’ukhal). The last three words of the verse are then translated "I have wearied myself, O God, I have wearied myself, O God, and am consumed."

See Ithiel.