I've added *frēgōną and *spurjaną as synonyms for *aiskōną. Today their descendants are used by multiple languages (e.g. German and Dutch use descendants of frēgōną, the North Germanic ones use descendants of spurjaną) to mean "to ask". Is it thus acceptable to list those words as synonyms?
I'm not sure if they were exact synonyms. *aiskōną seems to be more wanting to have something, while *frēgōną seems to be about wanting to know something.