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Irish ard
← Proto-Celtic *ardwos (inherited)
← Welsh ardd (cognate)
← Proto-Indo-European *h₃erdʰ- (root)
← Proto-Indo-European *h₃erdʰ- (inherited)
← Latin arduus (cognate)
← Old Irish ard (inherited)

→ English arduous (mention)
→ English McArdle (mention)
→ Irish airde (affix)
→ Irish ard-diúc (prefix)
→ Irish ardeaglais (prefix)
→ Irish ard-daonscoil (prefix)
→ Irish ardchlár (prefix)
→ Irish ard- (mention)
→ Irish ardréim (prefix)
→ Irish ardrúnaíocht (confix)
→ Irish ard-aire (prefix)
→ Irish ard-aireacht (confix)
→ Irish ardchaighdeáin (prefix)
→ Irish ardchathaoir (prefix)
→ Irish ardchúirt (prefix)
→ Irish ard-ghiúiré (prefix)
→ Irish ardeaspag (prefix)
→ Irish ardmháistir (prefix)
→ Irish ardfholús (prefix)
→ Irish ardiomrá (prefix)
→ Irish ardíomhá (prefix)
→ Irish ardlua (prefix)
→ Irish ardoideachas (prefix)
→ Irish ardmháistreás (prefix)
→ Irish ardmháta (prefix)
→ Irish ard-mhionoifigeach (prefix)
→ Irish ardsagart (prefix)
→ Irish ardteicneolaíocht (prefix)
→ Irish ardtiarna (prefix)
→ Irish ardtréas (prefix)
→ Irish ard-dílseacht (prefix)
→ Irish ardéirim (prefix)
→ Irish ard-reachtaire (prefix)
→ Irish ardghléine (prefix)
→ Irish ardchumhacht (prefix)
→ Irish ardteicniúil (prefix)
→ Irish ardmhinicíocht (prefix)
→ Irish ardmholadh (prefix)
→ Irish ardchultúr (prefix)
→ Irish ardchéimíocht (prefix)
→ Irish ardchríoch (prefix)
→ Irish ardtalamh (prefix)