The phrase "a rigid form" is correct and usable in written English.
It can be used to describe something that is inflexible or unyielding in structure or design.
Example: "The sculpture was crafted in a rigid form, making it difficult to alter or reshape."
Alternatives: "a strict structure" or "an inflexible shape".
We distrust the restrictions of a rigid form like opera seria.
Laïcité, a rigid form of secularism, has been integral to France's political identity since the Revolution, in the eighteenth century.
And, especially in this region, we're trying to impose a rigid form of paralysis, holding people in a framework that is not natural and didn't come from them.
In some quarters, a rigid form of multiculturalism also arose that challenged the need for immigrants and other minorities to identify with America at all.
So we continued to negotiate for a form, not such a rigid form, but a form of power-sharing at executive level; and the last proposal that we made was that there should be - in future from '99 onwards - if a party gets more than 50% of the vote, it forms the government.
The second involved drilling holes every two feet in his raft and running rope through them, so that the raft was lashed together like a basket — in other words, in a form that was supple, instead of a rigid form that could be battered apart in a storm.
The zaju, or variety play, was distinguished from the nanxi, or Southern drama (and later the chuanqi), by a more rigid form.
The Berbers, or Imazighen as they're called in their own tongue — Berber implies barbarian in Arabic — resisted the Arab conquest of the seventh century and still practice a less rigid form of Islam today.
ON THE face of it, anarchists, who believe in no government, have little in common with jihadists, who believe in imposing a particularly rigid form of government on everyone.
When it was immobilized, a more rigid form was acquired because of covalent linkages to the support.
