By Owen Gleiberman
Updated June 09, 2000 at 04:00 AM EDT

In Big Momma’s House, Martin Lawrence, playing an FBI agent who goes undercover as a sassy fat Southern grandma, wears dresses that look like frilly tablecloths, and he’s hidden behind wobbly jowls and pancake cheeks, a spongy upper lip, a pair of mountainous breasts, and arms that hang like Christmas hams. About all that’s left of Lawrence are his strikingly mismatched eyes — one innocent, one street-cool.

It may seem an act of desperation for a funnyman to put on this much of a costume, but then, a ”state of the art” makeup bodysuit can, in its way, be creatively liberating; it can force a performer to find fresh nuances within his comic voice. Robin Williams, as the title frump of ”Mrs. Doubtfire,” used a Scottish burr to wicked effect, sending one-liners coursing through the air like lethal Frisbees. And in ”The Nutty Professor,” Eddie Murphy had a mimic’s feast playing the gentleman blimp Sherman Klump and his cantankerous chorus of relatives.

By contrast, Lawrence’s performance in Big Momma’s House is every bit as broad and cartoony as his disguise. He gives Big Momma a high, faintly strangled delivery that’s a quaver away from George Jefferson’s; he doesn’t speak the lines so much as blare them. Every once in a while, this can be amusing, as when Big Momma offers a secretly lusty welcome home hug to Sherry (Nia Long), the grandchild she hasn’t seen in years, and lets slip with a courtly/lascivious, ”Oh, Big Momma could never forget that ass!” But that’s one of the only good bits in the movie, and it registers, even then, with forgettable flippancy. Lawrence doesn’t give Big Momma any special, hidden slyness, and that’s because he doesn’t appear to have any himself. There’s no ”there” beneath the makeup.

Most of the comedy derives from the way that Lawrence’s Agent Malcolm Turner, who is out to catch Sherry’s violent thief of an ex-boyfriend, scrambles to keep his glaringly overcranked impersonation undercover. There’s a fair amount of gratuitous noisy slapstick as well: Big Momma delivers a baby with oven mitts, cooks up a skillet full of pork chops using a fiery overdose of shortnin’, and smashes through a window to foil a crook. When Robin Williams and Eddie Murphy clowned around in those earlier ”head to toe makeup” comedies, there were moments when I thought I could feel the spirit of Peter Sellers hovering with wry approval. In Big Momma’s House, it’s closer to the spirit of Bozo.

Lawrence, in his early-’90s stand-up act, often came on like Murphy’s little brother, and he overplayed his eagerness to be applauded for prefab naughty-dog routines. Eagerness is Lawrence’s calling card: It’s what allows him to flip his personality, as if by on-off switch, from disgruntlement to jug-eared delight. Yet it doesn’t leave him with much of a center, or with the confidence to nail a joke by throwing it away. In formula crowd-pleasers like Blue Streak, Nothing to Lose, and now Big Momma’s House, Lawrence is so on that he appears to be gunning for clockwork bursts of audience approval. His movies make money, but he won’t be a true star until he exits the ”all shtick, all the time” zone. D+