1. (verb) engage by written agreement

• contract
• sign
• sign on

1. (verb) engage by written agreement

• contract out

2. (verb) join a club, an activity, etc. with the intention to join or participate,

• enlist

1. (verb) engage by written agreement

• employ
• engage
• hire

2. (verb) join a club, an activity, etc. with the intention to join or participate,

• fall in
• get together
• join

1. (verb) engage by written agreement

• contract
• signatory
• signer