Emblem directed at those people lacking height (5)
I believe the answer is:
totem
'emblem' is the definition.
(I know that totem is a type of emblem)
'directed at those people lacking height' is the wordplay.
'directed at' becomes 'to'.
'those people' becomes 'them' ('they' refers to a group of people).
'lacking' suggests deleting specific letters.
'height' becomes 'h' (abbreviation in geometry).
'them' with 'h' taken away is 'tem'.
'to'+'tem'='TOTEM'
(Other definitions for totem that I've seen before include "Natural item of spiritual significance" , "Venerated emblem" , "Object adopted by N American Indians as emblem" , "symbol of spiritual significance" , "Clan's emblem" .)