to sing with the alternation of two musical tonesa bluebird trilled outside our window
a bluebird trilled outside our window
quaver, warble
sluryodelbelt, carol, chant, chorus, croon, descant, harmonize, troll, vocalizelilt, scat
in the 14th century
英语同义词词典收录了63618条英语词条，基本涵盖了全部常用同义词或反义词的辨析及翻译，是英语学习的有利工具。