'Undersong' definitions:

Definition of 'Undersong'

From: GCIDE

Undersong \Un"der*song`\, n.
1. The burden of a song; the chorus; the refrain. --Dryden. [1913 Webster]
2. Accompanying strain; subordinate and underlying meaning; accompaniment; undertone. [1913 Webster]
In the very [poetry] there often an undersong of sense which none beside the poetic mind . . . can comprehend. --Landor. [1913 Webster]