Related Clues:

• Like the "h" in honor
• Soundless
• Win the support of
• Sign up for military service
• Like many old movies
• Gather, as volunteers
• Obtain as a volunteer
• Secure the aid of
• Mute
• Get on base?
• Be silent - join up
• Be silent and join up
• Unspeaking.
• Join up in silent way
• Noiseless