U+51F9 "凹" CJK Unified Ideograph-# Unicode Character

U+51F9 "凹" CJK Unified Ideograph-# is a Chinese character that primarily means "concave" or "indented," representing a surface that curves inward like a hollow or depression, and it is often used in contrast to its counterpart "凸" (convex). This ideograph appears in various East Asian languages including Chinese, Japanese, and Korean, where it is employed in contexts ranging from geometry and descriptions of physical shapes to idiomatic expressions and character components. Its structure visually suggests the concept of a dip or cavity, making it a pictographic representation of a concave form.

General Properties

Code Point	U+51F9
Version Added	1.1
Name	CJK Unified Ideograph-#
Block	CJK Unified Ideographs
General Category	Other Letter
Canonical Combining Class	Not Reordered
Bidirectional Class	Left To Right

Encodings

HTML Decimal Encoding	凹
HTML Hex Encoding	凹
UTF-8 Encoding	0xE5 0x87 0xB9
UTF-16 Encoding	0x51F9
UTF-32 Encoding	0x000051F9
C/C++/Java Escape	\u51f9

Unicode Properties

NFC Quick Check	Yes
NFD Quick Check	Yes
NFKC Quick Check	Yes
NFKD Quick Check	Yes
Numeric Type	None
Numeric Value	NaN
Line Break	Ideographic
East Asian Width	Wide
Script	Han
Script Extensions	Han
Indic Syllabic Category	Other
ID Start	Yes
XID Start	Yes
ID Continue	Yes
XID Continue	Yes
Alphabetic	Yes
Vertical Orientation	Upright
Grapheme Base	Yes
Grapheme Cluster Break	Other
Word Break	Other
Sentence Break	OLetter
Ideographic	Yes
Unified Ideograph	Yes

Unihan Properties

kBigFive	A557
kCCCII	21334C
kCNS1986	1-4577
kCNS1992	1-4577
kCangjie	SSU
kCantonese	aau3
kCihaiT	171.601
kCowles	30 2860
kDaeJaweon	0301.060
kDefinition	concave, hollow, depressed; a pass, valley
kEACC	21334C
kFanqie	烏洽
kFenn	650G
kFennIndex	589.09 617.02
kFourCornerCode	7777.0
kGB0	1628
kGB1	1628
kGradeLevel	4
kHangul	요:0N
kHanYu	10308.030
kHanyuPinlu	āo(31)
kHanyuPinyin	10308.030:āo,wā
kHKGlyph	0320
kIICore	AGTJHKMP
kIRGDaeJaweon	0301.060
kIRGHanyuDaZidian	10308.030
kIRGKangXi	0135.100
kIRG_GSource	G0-303C
kIRG_HSource	HB1-A557
kIRG_JSource	J0-317A
kIRG_KPSource	KP0-F9FD
kIRG_KSource	K0-686A
kIRG_TSource	T1-4577
kIRG_VSource	V2-8A4D
kJapanese	オウ ヨウ くぼむ へこむ ぼこ
kJoyoKanji	2010
kKoreanName	2015
kTGH	2013:260
kJapaneseKun	KUBOMU KUBOMI
kJapaneseOn	OU
kJis0	1790
kKangXi	0135.100
kKorean	YO
kLau	2272
kMainlandTelegraph	0425
kMandarin	āo
kMatthews	7268
kMeyerWempe	23 1968
kMojiJoho	MJ007441
kMorohashi	01810
kNelson	0664
kPhonetic	5
kRSAdobe_Japan1_6	C+1308+17.2.3
kRSUnicode	17.3
kSBGY	544.15
kSemanticVariant	U+20544<kLau
kSMSZD2003Index	55.02
kSMSZD2003Readings	āo粵aau3,nap1 wā粵waa1
kTaiwanTelegraph	0425
kTGHZ2013	004.130:āo
kTotalStrokes	5
kUnihanCore2020	GHJKMPT
kXerox	256:076
kXHC1983	0011.030:āo 1176.060:wā