inflexibleperson

noun
UK /ɪnˈflɛksɪbəl ˈpɜːsən/
US /ɪnˈflɛksəbəl ˈpɜrsən/

A person who will not change their mind or way of doing things.

My uncle is an inflexible person who always insists on eating dinner at exactly six o'clock.


OTHER MEANINGS

2. Someone who cannot bend or move easily because of stiff muscles or joints.

After the long flight, she felt like an inflexible person who could barely stretch her legs.

3. A worker or manager who refuses to adapt to new rules or methods.

The new software frustrated the inflexible person in accounting who wanted to keep using paper ledgers.

4. A person who sticks strictly to a routine and dislikes surprises.

As an inflexible person, he panics whenever his morning bus is late.