Is it ensure, insure, or assure?
mid-15c., "to howl like a dog," from Old Norse baula "to low like a cow," and/or Medieval Latin baulare "to bark like a dog," both echoic. Meaning "to shout loudly" attested from 1590s. To bawl (someone) out "reprimand loudly" is 1908, American English. Related: Bawled; bawling.