The meaning of the 戟 kanji in the context of 食戟


I read the manga "食戟のソーマ" and have a question concerning the meaning of the
[食戟]{しょくげき}. I understand the 食{しょく} part, standing for Food, but 戟{げき} is
what I don't understand.  
I would have understood it, if they used the Kun reading (ほこ) standing for
weapon, but as for 戟{げき} I have no idea. My question is: What is the meaning
of 戟{げき} in the contexts of 食戟 and therefore what does 食戟 mean?

Additional information: The official English title of this manga is "Food
Wars!". In the manga a 食戟 is a food competition, where cooks face each other
mostly in a one vs one fashion similar to Iron Chef but in a more over the top
style.




I asked two Japanese PhD students who knew the anime version. From the way it
is pronounced, they understood it as "Food Fight/Battle" and both would have
written it as 食撃 (like Ringil suggested in his comment). As for why the it is
written as 食戟 they had two similar opinions:

First, 戟 is outside of [Jōyō
Kanji](https://en.wikipedia.org/wiki/J%C5%8Dy%C5%8D_kanji) used in daily life
and therefore is special/unique/rare. This uniqueness would fit the topic
since all the dishes made during a 食戟 are special, one of a kind dishes.

The other argument was that in modern times with a huge competition in manga
books the work of the author needs to catch the attention of the reader at
first glance. And the first thing a reader sees is the cover with a title.
Using a rare character makes the reader curious about the word and its
meaning.

