plain Dunstable adjective 1noun 1forms 2 adjective1 •(no longer used) Straightforward, honest.Why, master Thorney, do you mean to talk out your dinner ? the company attends your coming . What must it be, master Frank ? or son Frank ? I am plain Dunstable. — 1621 noun1 •(no longer used) straightforward language; straight talk.Because I value Mr. Solmes as my friend, you treat him the worse — That's the plain Dunstable of the matter, Miss! — I am not such a fool but I can see that. — 1748 formsmore plain Dunstable · most plain Dunstable