Correct

筒子

/ tǒngzi / 
Strokes

Definition

tube-shaped object/tube/bobbin/(Internet slang) homonym for 同志[tóng zhì]

Example

As a Noun

tube; tube-shaped object

1
Xuētǒngzi
靴筒子

leg of a boot

2
Qiāngtǒngzi
枪筒子

barrel of a gun