Harpoon

[Sarah]

A harmonica (southern argot/slang?)

[Sarah]

For [seamen] the call of Harpoon! is a call of distress when a particularly dangerous sea monster is approaching their vessel. In modern culture this is used by young males to communicate their concern for an inebriated friend being attracted to a morbidly [obese] or outrageously unattractive female or [transvestite].

[Sarah]

1. Weapon used for killing whales.

2. Alcoholic beverage made of Gatorade and Captain Morgan's Parrot Bay. The ultimate Drink.

[Sarah]

a syringe to shoot drugs

[Sarah]

What you man when there's a whale about.

[Sarah]

Harpoon is slang for a hypodermic syringe.
Medically, the harpoon is described as the rod that is used to push the contents through the needle.

[Sarah]

The battle cry called out to alert members of ones team that a shoulder launched rocket is going to be fired. In reference to the [Rocket Propelled Grednade] ([RPG]) looking like a whaling tool on some online applications.

[Gregory]

A barbed missile resembling a spear that is attached to a long rope and thrown by hand or fired from a gun, used for catching whales and other large sea creatures.

[Tracie Lynn]

Financial goal-setting, time-tracking, and invoicing app for freelancers and consultants. Track expenses, get paid online. A software product by Harpoon

[Sarah]

a long, heavy spear (= a long, sharp weapon) attached to a rope, used for killing large fish or whales