undersang

Verb

undersing (third-person singular simple present undersings, present participle undersinging, simple past undersang, past participle undersung)

1. (ambitransitive) To sing inadequately, or with too little vocal effort.
   • …the enthusiastic borderism of Scott, who, rather than that a freebooter should under-act his part, or a bard undersing his praise, took the liberty of sometimes inventing the action and then resounding its glories, and debiting both to the account of originals, quite innocent of either.1858, “The Ballad Poetry of Scotland—Professor Aytoun” (review) in MacPhail’s Edinburgh Ecclesiastical Journal, no. 152
2. (transitive) To sing beneath, or in accompaniment to; to sing an undersong.
   • Alas me! what a murmur and motion I hear,
     As of birds flying near!
     And the air undersings
     The soft stroke of their wings—
     And all life that approaches, I wait for in fear.1851, Elizabeth Barrett Browning, Prometheus Bound