1. (n.)conjecture the formation or expression of an opinion or theory without sufficient evidence for proof.
2. conjecture an opinion or theory so formed or expressed; speculation; surmise.
3. conjecture Obs. the interpretation of omens.
4. (v.t.)conjecture to conclude or suppose from evidence insufficient to ensure reliability.
5. (v.i.)conjecture to form conjectures.
Etymology: (1350–1400; ME (< MF) < L conjectūra inferring, reasoning =conject(us) ptp. of conjicere to throw together, form a conclusion (con-con - +-jicere, comb. form of jacere to throw) +-ūra -ure)
Definition of 'conjecture'
Princeton's WordNet
1. (noun)speculation, conjecture a hypothesis that has been formed by speculating or conjecturing (usually with little hard evidence) "speculations about the outcome of the election"; "he dismissed it as mere conjecture"
2. (noun)guess, conjecture, supposition, surmise, surmisal, speculation, hypothesis a message expressing an opinion based on incomplete evidence
3. (verb)conjecture reasoning that involves the formation of conclusions from incomplete evidence
4. (verb)speculate, theorize, theorise, conjecture, hypothesize, hypothesise, hypothecate, suppose to believe especially on uncertain or tentative grounds "Scientists supposed that large dinosaurs lived in swamps"
Definition of 'conjecture'
Webster Dictionary
1. (noun)conjecture an opinion, or judgment, formed on defective or presumptive evidence; probable inference; surmise; guess; suspicion
2. (verb)conjecture to arrive at by conjecture; to infer on slight evidence; to surmise; to guess; to form, at random, opinions concerning
3. (verb)conjecture to make conjectures; to surmise; to guess; to infer; to form an opinion; to imagine
Definitions of conjecture 
Afrikaans: gissing, onderstelling; k
Arabic: تَخْمين، ظَن، حَدَسِيَّه
Bulgarian: догадка
Brazilian: conjectura
Czech: domněnka, dohad
German: die Mutmaßung
Danish: formodning; gætteri
Greek: υπόθεση
Spanish: conjetura, suposición
Estonian: oletus
Farsi: حدس؛ گمان
Finnish: arvaus
French: conjecture
Hebrew: הַשעָרַה, נִחוּש
Hindi: अनुमान
Croatian: nagađanje, naslućivanje
Hungarian: sejtés
Indonesian: dugaan
Italian: congettura
Japanese: 推測
Korean: 추측, 짐작
Lithuanian: spėjimas, numanymas
Latvian: varbūtība; pieņēmums
Malay: teka
Dutch: gissing
Norwegian: antakelse, gjetning, form
Polish: domysł, przypuszczenie
Persian: حدس؛ گمان
Pashto: اتکل
Portuguese: conjectura
Romanian: presupunere
Russian: предположение
Slovak: dohad
Slovenian: domneva
Serbian: pretpostavka
Swedish: gissning, hypotes
Thai: การคาดเดา
Turkish: tahmin
Taiwanese: 猜測
Ukrainian: припущення, здогад
Urdu: قياس، اندازه
Vietnamese: sự phỏng đoán
Chinese: 猜测
