Is mayo mayonnaise if it doesn’t contain eggs?

The food giant Unilever thinks not. And it is suing Hampton Creek, a start-up company making an eggless spread that tastes like mayonnaise, accusing it of false advertising and fraud.

Hampton Creek, whose investors include Bill Gates, the Hong Kong billionaire Li Ka-shing and prominent venture capitalists, replaces eggs with yellow peas in its spread, which is called Just Mayo.

In its lawsuit, Unilever contends that Just Mayo is denting sales of its popular mayonnaise products, known as Hellmann’s in the East and Best Foods west of the Rockies.

Just Mayo has rapidly won distribution in giant retail and grocery chains like Target and Walmart, and Hampton recently began selling Just Cookies, an eggless, dairy-free cookie dough in four varieties.