"Help" means helping a teammate accumulate free lives.

You can help every player once for every life request. When a player gets the 5 lives they requested, the asking lives bar disappears from the chat.

In the “My Guild” section, you can see how many times a player on your guild has helped other guild mates.

On the Guild Info pop-up, it shows the weekly helps of a team. This shows how many times free lives were sent in that guild during the week.