There are 10 words that start with 'polyn'.
| polynya | polynyi | 
| polynyas | polynomial | 
| polynomials | polynuclear | 
| polyneuritis | polyneuritises | 
| polynucleotide | polynucleotides | 
Note: These 10 words that start with 'polyn' are found from the USA & Canada version of the tournament Scrabble word list.