daijs says it corresponds to ザクースカ, which is the russian equivalent of an hors d'oeuvre, served smorgasbord style:
http://en.wikipedia.org/wiki/Zakuski
=
still, i think the key point is that it's an appetizer, and smorgasbord is potentially misleading

no reason for plurals, either.

@@ -16,6 +16,4 @@
-<gloss>relishes</gloss>
-<gloss>hors d'oeuvres</gloss>
-<gloss>smorgasbord</gloss>
-<gloss>appetizers</gloss>
-<gloss>appetisers</gloss>
-<gloss>starters</gloss>
+<gloss>hors d'oeuvre</gloss>
+<gloss>appetizer</gloss>
+<gloss>appetiser</gloss>
+<gloss>starter</gloss>

Adding:
appetizers; appetisers; starters

"smorgasbord" doesn't seem right.
If it's right it should be a second sense.
I think "smorgasbord" is a meal rather than something you have at the start of a meal ~ 
"a meal at which you serve yourself from a large range of hot and cold dishes"
.
Come to think of it, "relishes" doesn't sound right either? 
"a spiced side dish or accompaniment to food"
That doesn't seem to match what Kodansha says, for example:
前菜 [ぜんさい] ★ 食事の最初に出される軽い食物。通し。つきだし。オードブル。

@@ -19,0 +19,3 @@
+<gloss>appetizers</gloss>
+<gloss>appetisers</gloss>
+<gloss>starters</gloss>