Uu

Underline:

A line under something, such as a symbol, word, or phrase, used to indicate emphasis or italic type.

Subrayar:

Hacer una raya debajo de una letra, una palabra o una frase escrita, para resaltarla.

Tomado de: (Google definiciones, 2.016).

Underline - Subrayar
Tomado de: (Google imagenes, 2.016)

Simple form	Third Person	Simple Past	Participle	Gerund
Underline	Underlines	Underlined	Underlined	Underlining