Land also at sea (4)
I believe the answer is:
laos
'land' is the definition.
(Laos is an example)
'also at sea' is the wordplay.
'at sea' is an anagram indicator.
'also' anagrammed gives 'LAOS'.
(Other definitions for laos that I've seen before include "Country of Indo-China, capital Vientiane" , "Asian country, capital Vientiane" , "Country of SE Asia" , "Mountainous state in southeastern Asia" , "Indo-Chinese country" .)