The lamp has a heavy base.

这盏灯的底座很沉。

《牛津词典》

The lamp has a flat base.

这个灯座是平的。

youdao

The base of the lamp unscrews for wiring and mounting.

台灯的底座可以拧开来进行布线和安装。

youdao

Today, there is a wide range of LED bulbs available at IKEA that enable customers to easily change old incandescent bulbs to LED without changing the lamp base.

ENGADGET: Ikea to sell only LED-based lighting by 2016, wants to be greener than your sofa bed

Soon, lamp-warmed burgers were fanning out from the McDonalds' Californian base.

ECONOMIST: As hamburgers go, so goes America?