Adler's apparatus notes that this headword, oi)kei=lai, is (slightly) out of alphabetical order in the position it occupies. But in truth it is under the wrong letter altogether, since it should be o)kei=lai. This aorist infinitive of the verb o)ke/llw (or ke/llw) occurs in Thucydides 4.12.1 (see web address 1); it also appears in sigma 703 (and see also sigma 1806).
Likewise in other lexica; references at Photius omicron85 Theodoridis.