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

There is a metal ball on bottom of each metal strip that makes up lamp base.

在底部有一个金属球，弥补了每个灯带金属基地。

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

Some winding blocks away from my home base, I spotted in the light of a street lamp a promising trove an unusually large pile of curbed junk that could have passed for an installation in a Chelsea gallery.

NEWYORKER: Wakefield

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

ECONOMIST: As hamburgers go, so goes America?