There are 11 words that start with 'invar'.
| invar | invars | 
| invariant | invariable | 
| invariably | invariance | 
| invariants | invariables | 
| invariances | invariability | 
| invariabilities | |
Note: These 11 words that start with 'invar' are found from the USA & Canada version of the tournament Scrabble word list.