They made a verbal agreement, but nothing was written down.

verbal 是形容词，来自名词 verb（动词），意思是"与言语有关的"或"口头的"。 agreement 是名词，来自动词 agree（同意），意思是"协议、协定"。 verbal agreement 指通过口头交谈达成的协议，没有书面文件记录。