Incendiary material from an upturned hand (6)
I believe the answer is:
napalm
'incendiary material' is the definition.
(incendiary chemical)
'an upturned hand' is the wordplay.
'upturned' says the letters should be written backwards.
'hand' becomes 'palm' (I've seen this before).
'an' reversed gives 'na'.
'na'+'palm'='NAPALM'
'from' acts as a link.
(Other definitions for napalm that I've seen before include "Flame-thrower jelly" , "Flammable jelly used in weapons" , "Firebomb jelly" , "Incendiary weapon" , "Incendiary bomb jelly" .)