What's the difference between polytheism and polytheistic?

Polytheism

Definition:

• (n.) The doctrine of, or belief in, a plurality of gods.

Example Sentences:

• (1) He rejected what he saw as pagan accretions introduced by bid’a (innovation) and shirk (idolatry or polytheism), which detracts from the absolute transcendence of God.

Polytheistic

Definition:

• (a.) Alt. of Polytheistical

Example Sentences:

• (1) The influence of Wahhabism meant that 90% of Islamic monuments, holy places, tombs and mausoleums in the Arabian peninsula were destroyed on the grounds that they were “polytheistic”.
• (2) Of the estimated 200,000 refugees, many have reached towns in the Kurdish zone, where emergency supplies are running low; others are stranded on the mountain , dying of hunger and thirst but too afraid to move, aware that IS is killing Yazidis it finds or forcibly converting them to Islam, since it sees them as “polytheists” or – worse – “devil worshippers”.
• (3) It has also destroyed significant portions of the ancient heritage of Iraq’s Assyrian community, Shia and Christian shrines that Isis says are polytheistic and contrary to its brand of puritanical Islam.
• (4) "Is he a Bayern Munich fan as his birthplace might indicate, or is he as polytheistic as his predecessor?
• (5) "It's the fact of the jihad, the preparation of the jihad, the fighting of the jihad, this is what causes terrors inside the hearts of the mushrik [polytheists] and even the enemies that you don't know," he added.