# GDScript: Reuse a Definition

Source: https://tweens.gd/gdscript/definitions/

A tween definition is a motion you can re-use on any compatible Node.

Interactive preview: https://tweens.gd/gdscript/definitions/

## Scripting it

In a 2D scene, drag `icon.svg` into the viewport a few times, side by side. Attach this script to the scene’s root `Node2D` and run it.

hop\_wave.gd

```gdscript
extends Node2D

func _ready() -> void:
  var hop := Tweens.position_2d_y()
  hop.by_value = -80.0
  hop.duration = 0.25
  hop.ease = Out.QUAD
  hop.ping_pong = true

  var icons := get_children()
  for i in icons.size():
    Tweens.play(icons[i], hop.with_delay(i * 0.2))
```

1.  **Define once.** `hop` lifts a node 80 pixels and drops it back; negative y is up in Godot. `by_value` is relative, so each icon hops from wherever it stands.
2.  **Find the nodes.** Every child of this node.
3.  **Start a copy on each.** `with_delay()` copies `hop` with a new delay, so `hop` itself keeps none. Each start returns its own handle.

Each start snapshots its definition. Change `hop` later, and only the starts after that follow; tweens already playing keep their settings.

### Would you like to know more?

[Anatomy](https://tweens.gd/gdscript/anatomy/)Every field a definition can set.

[Variations](https://tweens.gd/gdscript/variations/)Scale or shift a copy relative to the original.

Keep reusable motion nearby

Store a shared definition in a `static var` in a class you can use as your animation design system (or theme), shared across your project. Treat it as read-only and use `with_*()` copies for individual starts.