gg5
 ·〔息子が父親に向かって〕 そんなこと言うなんてお父さんは頭が古いよ.　That's an out-of-date [old-fashioned] way of thinking, Father.
 ·頭が古い人は, 女性の上司なんてとんでもないと思うだろう.　Traditionalists [The old guard, 《口》 The oldies] must find the idea of having a woman as boss totally unacceptable. ｜ People with the old way(s) of thinking would presumably be totally opposed to having a woman as their superior.

i agree, but gg5's example don't seem particularly derogatory.  hesitant to mark it as such without direct evidence to the contrary

@@ -13,2 +13,1 @@
-<misc>&derog;</misc>
-<gloss>being old-fashioned in one's way of thinking</gloss>
+<gloss>old-fashioned (in one's way of thinking)</gloss>

daijs, daijr

Sound derogatory but mostly a guess