The word ikhlas means 'sincerity'. It is the name of a surah (chapter) in the Quran. This chapter is also known by the name 'tawheed', which means unity.

(Chapter 112. The Unity)

In the name of Allah, Most Gracious, Most Merciful
[112.1] Say: He, Allah, is One.
[112.2] Allah is He on Whom all depend.
[112.3] He begets not, nor is He begotten.
[112.4] And none is like Him.