síkkal

Síkkal is the instrumental/comitative case form of the Hungarian noun sík, which means "plane" or "flat surface." As an inflected form, síkkal expresses accompaniment, instrumentality or spatial relations involving a plane, commonly translated as "with the plane" or "by the plane." It is used in descriptions of geometric relations, contact, or movement relative to a surface.

Morphologically, the form arises from adding the Hungarian comitative suffix (traditionally rendered as -val/-vel) to the stem sík, with consonant assimilation producing a doubled consonant (k → kk), yielding the surface form síkkal. Functionally it appears in constructions such as geometric statements (e.g., describing parallelism or intersection) and in phrases indicating contact or accompaniment.

Examples in Hungarian include A fény a síkkal párhuzamos ("The light is parallel with the plane") and A lemez síkkal érintkezik ("The sheet is in contact with the plane"). Related forms of the lemma sík include the nominative sík, the inessive síkban ("in the plane"), the superessive síkon ("on the plane"), and possessive or plural inflections used in technical and everyday contexts.

Síkkal is primarily encountered in mathematical, physical and descriptive texts where precise spatial relations to a flat surface are relevant.