Through the ages, a Spade was most commonly known as a tool.
The word Spade has been derived as a variation from the
words below:
SPADE:
German- A tool for digging (Shovel).
SPADER: German- occupational name for a SPADE maker it for someone woo used a SPADE in their work.
SPAIDE/SPAID: American variation of German SPADE.
SPADA:
Italian- from SPADA "Sword" metonymic occupational name for an armoured
man or swordsman or nickname for summertime who resembles a sword in some way.
SPADEA:
Italian- from Greek Spadéas "Swordsmith".
SPADE has also been known to be defined as "Blade of the sword" which loosely translated to "strength". This version was more commonly used in medieval times.
Its original spelling, pronunciation and cultural foundation is unknown.
Needless to say, Spade is a very old word.