3 letters

agn fgn Rgn tgn

4 letters

cagn sign ∙

5 letters

Thegn ∙ baign deign ∙ feign ∙ reign ∙ Align ∙ coign ∙ soign ASRgn

6 letters

telegn Droggn Araign indign ∙ sdeign ∙ malign ∙ benign ∙ eloign ∙ proign ∙ obsign ∙ design ∙ resign ∙ ensign ∙ Cosign ∙ Assign ∙ repugn ∙ impugn ∙ oppugn ∙ expugn ∙

7 letters

impregn ∙ deraign ∙ arraign ∙ condign ∙ endeign refeign dereign rereign coreign ∙ foreign ∙ realign ∙ esloign almoign essoign subsign presign consign ∙ propugn

8 letters

campaign ∙ darraign ∙ misfeign ∙ outreign ∙ disalign misalign ∙ unbenign ∙ gascoign disloign ∙ redesign ∙ InDesign undesign codesign ∙ coresign foresign autosign reassign ∙ postsign

9 letters

champaign ∙ sovereign ∙ unforeign predesign ∙ Ecodesign outdesign ∙ reconsign ∙ undersign ∙ preassign ∙ misassign ∙

10 letters

recampaign nonforeign proforeign interreign invisalign foredesign overdesign ∙ preconsign foreassign

11 letters

precampaign unsovereign cosovereign semiforeign antiforeign ∙ superbenign Countersign ∙

12 letters

subsovereign nonsovereign frankalmoign ∙

13 letters

demisovereign

14 letters

undersovereign supersovereign

15 letters

countercampaign ∙

Words with a ∙ are valid Scrabble words (SOWPODS word list)